The eye disease that caused Bill Cosby to go blind

Meagan Morris is an entertainment and lifestyle journalist living in New York City. In addition to SheKnows, Morris contributes to many publications including The New York Times, Yahoo! News, PopEater, NBC New York and Spinner. Follow he...

A source told Page Six that the actor is homebound and relies on his wife to work on his legal issues. Cosby was charged with three counts of felony aggravated indecent assault for allegedly assaulting former Temple University employee Andrea Constand in 2004, “He is confined to his house in Pennsylvania, and the only person on his side is his wife, Camille, who is masterminding his defense," the source said.

The reason for the decline in Cosby's eyesight is a condition called keratoconus, according to Page Six. Keratoconus (often called KC) is a non-inflammatory eye condition caused by the thinning of the cornea and eventually causes a cone-like bulge, according to the National Keratoconus Foundation. Though it's not common, about one in every 1,000 people develops KC and it's typically diagnosed during late adolescence.

In early stages, KC shows with symptoms like "ghosting, multiple images, glare, halos, starbursts around lights and blurred vision," according to NKF. These visual distortions and sensitivity to light progress over the next 10-20 years and special contact lenses are needed to correct the symptoms. In later stages, a corneal transplant may be required. It doesn't often to lead to complete blindness, according to Keratoconus Australia.

It's unclear how long Cosby has experienced keratoconus or if he really has it, but recent photos — including his 2015 mug shot — do show an abnormality in one of his eyes.

If you're having symptoms of KC, it's important to get to an eye doctor — stat. Treatment can do amazing things and many people with it experience full, rich lives afterward.

"My life, in just a few short weeks, has been irrevocably changed. We are still working out the fine tuning, but the vision restored is unbelievable," Rene Vasquez wrote in a blog for The Discovery Eye Foundation of his KC treatment. "I never thought I would see this well again."